This is a topic which I am having alot of trouble with. Typically to implement qos on a switch I just use the Auto QoS but in this case it does not apply.
Lets say we have two switches connected over a WAN 100Mpbs Layer 2 link. I want to provide QoS on this link which connects the two sites. There is no voice or video, the only thing I want to do is guarantee bandwidth to a a few specific VLANS.
The switches in question are the Cisco Catalyst Blade Switch 3120
The following is what I have configured but I am unsure if this will work or make things worst.
I start by mapping the the COS values in to some queues
mls qos map cos-dscp 0 8 16 26 32 46 48 56
mls qos srr-queue output cos-map queue 1 threshold 1 0
mls qos srr-queue output cos-map queue 2 threshold 1 5
mls qos srr-queue output cos-map queue 3 threshold 1 1
mls qos srr-queue output cos-map queue 4 threshold 1 2
*Here I want cos value 0 in Queue 1, 5 in Queue 2 and so on
Then I applied the mls qos cos # to the interfaces where i wont to tag the cos traffic
ex) Database interface is gi 1/0/5
mls qos cos 5
Next I apply my outbound queue settings. The link that connects the two sites is gi1/0/26
description LINK TO OTHER SITE
switchport mode trunk
srr-queue bandwidth share 35 45 15 5
* Here i assume it will give 35% of bandwidth to queue 1, 45% to queue 2, and so on.
Can anyone see anything major I may have missed? I know I have not set threshold values but I assume the defaults will do.